TW461164B - A semiconductor laser device - Google Patents

Abstract

An optical semiconductor device comprising, an active region; and a p-doped cladding region disposed on one side of the active region; wherein an electron-reflecting barrier is provided on the p-side of the active region for reflecting both Γ-electrons and X-electrons, the electron-reflecting barrier providing a greater potential barrier to Γ-electrons than the p-doped cladding region.

Description

Amend

(> 4 6 116 4 Case No. 88121986 V. Description of the invention 0) Technical scope The present invention relates to optical semiconductor devices, especially, but not exclusively, semiconductor laser devices that emit visible light between the ancient wavelength range of 630 nm to 680 ηηι. f Off 'This laser device can be edge-emitting or surface-emitting. Greedy technology is made of P-type (A1, Ga, In) materials, and laser devices or laser diodes (LDs) that emit about 63nm_6nm f ^^ visible light have become increasingly important for professional products. Important components, such as: foreseeable digital audio discs (DVD) will use ^ which can produce 30㈣ input, wavelength 6 35 n „_6 5 0 nm. The next $ 2 = radiation requires higher maximum power output 'higher The operation, s 乂 j 田 〇c). The degree of n (such as 7 〇 (. P type means that its family of compounds have a general formula (A y I nyp, where x and y are both between 〇 Between 1. A particular advantage of this system is that when the indium mole fraction "y" is equal to the semiconductor, it will match the lattice of the GaAs substrate.; · 48 Current (A 1, Ga, I n) P laser The theoretical limit of the diode is that it cannot operate for a long time at a specified operating temperature (or there is a phase f Λ at a higher current). In general, it is believed that this is because of the criticality of the active region of the electron slave device and the surrounding optical conduction region. And then it flows into the P-shaped cladding area and weaves it out and leaks until there is a laser device to limit the heterojunction for separation Laser, Figures 1 and 2 illustrate the general structure that can produce visible light with a wavelength of 630-680 nm, which will be referred to in 4 sec. The general structure of laser fabrication (the curve (a) of Figure 1 illustrates (AlxGahhwIno.uP and Ga〇52ln ' The difference between the energy of the electric band is used as the Γ guide fraction of ^ / 48P in the quaternary alloy.

461164 r--year, month and day "__ V. Description of the invention (2) f-number. The curves (b) and (C) in Figure 1 show the difference between the energy of the X conduction band and the energy of the Γ conduction band, respectively. Figure 1 Assume that the band gap difference between (Al, Ga) InP and GalnP will be separated into a ratio of 7 0: 3 0 between the conduction band offset and the valence band offset. This shows that (A 1, Ga, I n) The minimum energy in the P-conducting band is a function of the aluminum content. At a concentration of about 0.55, an intersection is formed from the minimum Γ band to the minimum X-band. Here, the two terms "1" and "X-band" are used as The point of symmetry in the Brillouin region, + is a standard vocabulary in solid state physics, please refer to "Semiconductors" by RA Smith (Cambridge University Press, 1 78) The two minimum terms r (r_minimun) and minimum: X (X-minimum) are the minimum energy levels of the Γ band and the X band, respectively. FIG. 2 is a schematic band structure of a separation-limited laser structure manufactured in an (Al, Ga, ιη) ρ system, which includes an η-doped (A1q 7Ga. 3) fl 52lnfl 48ρ region 1, and (AluGauh.wIn). 48ρ optical guide region 2,4, Gal nP quantum potential well active region 3 deposited in (A1.ja ο · 5) .521 no.48P optical guide bow region, and mouth doping (person 1.) 7〇 & () _ 3) () 52 1 11 () 48? Covered region. Optical transfer caused by Γ electrons in (; 311 ^ quantum potential well active region) will excite laser. Diode quantum potential Laser action in the active region of the well 3. The electron leakage current contains an electronic fraction with sufficient thermal energy to pass through the potential blocking layer on the right-hand side of FIG. 2 and enter the P-doped cladding region 5. We can see that only the A potential blocking layer of approximately 90 me V on the interface of the hetero-cladding region can confine the Γ electrons to the optical guiding region (light guiding region). This relatively small barrier layer height allows a sufficient proportion of electrons to escape. The holes in the valence band are limited only by a potential barrier of approximately 50 meV

O: \ 61 \ 61877.ptc Page 5 461164 ___ Case No. 88121986 Birth Month Day Amendment __ V. Description of the Invention (3) Layer ’This low barrier height also allows a sufficient number of carriers to escape. Furthermore, the X conduction band in the P-doped cladding region 5 is 50 me V lower than the Γ conduction band in the light wave guiding regions 2 and 4, which allows electrons to escape from the light wave guiding regions 2 and 4 to pass through p. Permanent states in doped cladding regions. Therefore, the laser device illustrated in Fig. 2 has a high leakage current 'and therefore has poor performance at high temperatures. PM Smowton et al., In ".Appli.ed Physics Letters", Volume 67, 1265-1267 (1995), show that the important leakage mechanism of electrons can be separated to limit the p-side guidance of the heterostructure laser and the inner guidance of the coating area. The X Valley of the belt, where the laser has two Gafl 41inQ 59p quantum potential wells separated by a barrier layer, or an optical guide set at (AlyGai_y) fl51In (). 4gP (where y can be 0.3, 0.4, and 0.5) The region is covered with (A 1 〇7Ga0 3) 0521 nQ 48P, and the region is doped with Zn on the p-side and Si on the η-side. However, ‘has not made a proposal to alleviate the problems caused by the loss of electronics through this agency. Many proposals have been made to improve the high temperature performance of laser devices manufactured in (Al, Ga, In) P systems. T, T a k a g i, et al., In "I E E E J 〇 r n a 1 f f q u n t um electronics" Vol. 27 No. 6 p. 1511 (1991) proposed the introduction of a multiple quantum potential well barrier layer in the cladding region. In British Patent No. 9526631.8, it is proposed to insert a 5 doped p-type layer in the p-doped cladding region of the SCH laser diode, which has the effect of increasing the bending on the P side of the heterojunction, This can increase the potential blocking layer for electron heat leakage. G. H a t a k 〇 s h i et al. Proposed the addition of a P-doped packet in "I E E E J 〇 u r n a 1 〇 f Q u an t um Electronics", Volume 27, page 1476 (1991)

O: \ 61 \ 61877.ptc Page 6 461164 ---- Case No 88121986__Year Month Day__Amendment ___ 'V. Description of the invention (4) The degree of doping of the cover area to increase the light guide area and A potential blocking layer between P-doped cladding regions. British Patent No. 9 62 6 644. 0 discloses a semiconductor laser incorporating an electron reflection layer to prevent X electrons from escaping into the P-doped cladding region. British Patent No. 9 6 2 6 6 5 7. 2 discloses the use of an electron capture layer to capture electrons and transfer them to the Γ-limited energy level in the active region. However, the effects of these methods on improving the temperature characteristics of (Al, Ga, In) P laser devices are currently unknown. The operating principle of the multiple quantum potential well barrier (MQB) is to incorporate the MQB into the p-type cladding region of the SCH laser device. MQB contains another very thin (In, Ga) P and (A1, Ga, In) P (for (A1, Ga, In) P laser) layers. The electrons with sufficient energy to escape from the SCH structure will mechanically reflect the quantum on the two interfaces of the MQB. If the layer thickness is chosen to be the thickness of / 4 'where; I is the electron wavelength, and then the energy band can be planned as The electrons will reflect with a probability of 1. The only reflection of the electrons can be planned almost to an existing potential well above the height of a conventional barrier. Theoretically, MQB increases the effect of the barrier height by a factor as high as 2 compared to the traditional barrier height. K. Kishino et al. Provide evidence in "Applied Physics Letters" volume 58 1822-1824 (1991) and H. Hamada et al. In "Electronics Letters" volume 28 1 834-1 83 6 (1 9 92) It is shown that the critical current of short-wavelength lasers can be improved by using such a reflection device without being affected by temperature. However, the effect of the reflection device is inferred from the operating characteristics of the LD, rather than directly measured from the increase in the height of the barrier layer, so it is difficult to order compared with any place obtained due to better processing or better material quality. What are the benefits of using MQB. Go one step further

461164 ___ Case No. 88121986 V. Description of the invention (5)

Please note that the effect is only in the electronic connection. Anything that destroys this coherence significantly reduces reflection characteristics. When the length is very long, something called 3 (such as the interface spreading out) will

In other words: The degree of impurity will increase the potential blocking layer between the light guide region 4 and the P-doped cladding region 5, ρ Ιη) P or (A1, Ιη) P cladding region? Doped into a mixture of Ga and y. This is especially applicable to MOCVD growth materials. * The practical limit of z and M is about the gastric cml impurity concentration,

There are 14 types of examples in the Journal of Quantum Electronics, Volume 30, pages 593-6606 (1 994). However, using this technique to further increase the dopant concentration will cause the dopants to diffuse into the active area of the device. As a result, its effectiveness is reduced. In order to increase the potential between the light-wave guiding region 4 and the p-doped cladding region 5, the so-called blocking layer 'can increase the aluminum content of the cladding layer 5 so as to increase the r electron and valence band hole limitation. This method is illustrated in FIG. 3, which illustrates similar to the SCH laser structure ' shown in FIG. 2 except that its cladding regions 1, 5 are made of A11nP. At this time, the potential blocking layer between the optical guiding region 4 and the ρ-doped cladding region 5 is 250 m e V, and the valence band hole limited by the potential blocking layer is 100 ^ e V. Therefore, the structure of the laser junction shown in Fig. 3 has been improved compared with the structure shown in Fig. 2. The limitation of the barrier layer has been improved. Summary of the Invention A first field of the present invention provides an optical semiconductor device including: an active region and a p-doped cladding region deposited on one side of the active region, wherein an electron reflection blocking layer is provided on the P side of the active region, Used to reflect Γ electrons and X electrons.

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O: \ 61 \ 61877.pt Page 9 2001.06.13. 009 461164 Case No. 8812 1986 ^ Month 〇 Revised month repair-Λι V. Description of the invention (7) The problem of state loss carrier, or at least significantly reduce this The problem is that the X-electron and Γ-electron are reflected by the electron reflection layer. The electron reflection layer includes a first electron reflection layer for reflecting Γ electrons, and a second electron reflection layer for reflecting X electrons. This is the most convenient way to provide a blocking layer to the Γ electrons and X electrons. At least one electron reflecting layer is a strained layer. In some cases, the strained semiconductor layer has a forbidden band gap, which is greater than the forbidden band gap of a large number of semiconductor materials. Using such a strained layer as an electron reflecting layer can increase the And potential blocking layer for hole leakage. One electron reflecting layer may be in a compressive strain state, while the other electron reflecting layers may be in a tensile strain state, so the two electron reflecting layers will form a strain compensation barrier layer. It is reported that the strain compensation barrier layer can be made better than the individual layers. The sum of the critical thickness is also thick without introducing defects into the layer. This means that the strain-compensated electron reflection blocking layer can be made a little thicker without defects, and a thicker barrier layer will reflect more electrons back to activity This device can be used to increase the electron limit. This device can be a light-emitting diode or a laser device. The laser device can be a separate-limiting heterostructure laser device. It includes an optical guide area and the activity deposited in the optical guide area. Region. The Γ electron reflection layer can be deposited between the optical guidance region and the X electron reflection layer. The Γ conduction band of the optical guidance region generally deteriorates with the X conduction band of the Γ electron reflection layer. This ensures that Γ electric 1 The sub-reflection layer does not generate a quantum potential well for X electrons. In addition, the Γ electron reflection layer is deposited between the X electron reflection layer and the P-doped cladding region. Here Built-in manner, electrons in the Γ X formed electronically reflective layer, a quantum well potential does not cause a serious problem, because they can reach the electron Γ

O: \ 61 \ 61877.ptc Page 10, 2001.06.13.010 461164 _ cable number 88121986_ year month day _ϊ ± £ -_ V. Description of the invention (8) The reflective layer has very few electrons, so the optical guide of this configuration is very light. Leading areas allow the use of many materials. The electron reflection layer includes a plurality of first electron reflection layers for reflecting Γ electrons, and a plurality of second electron reflection layers for reflecting X electrons. The electron reflection blocking layer may have a supercrystalline lattice structure, and it is possible to form this structure because the electron blocking layer is strain-compensated. This device can be made in the (A1, Ga, Iη) P system, the Γ electron reflection layer can be A1P or GaP, and the X electron reflection layer can be InP, which provides a convenient reduction (A 1, G a, I η) Method of leakage current in a laser. The Γ electron reflection layer may be A1P and the optical guidance region may be (AluGa ^ h. ^ In .. ^, which makes the Γ conduction band of the optical guidance region generally deteriorate with the X conduction band of the Γ electron reflection layer. This is the best when the Γ electron reflection layer is deposited between the optical guide area and the X electron reflection layer. The thickness of each electron reflection layer is about 16A or less, this thickness is lower than the critical thickness, and the strained layer is critical here. Uneven chaos will be formed in the thickness and excess energy will be formed. At least one electron reflection layer is P doped. If the electron reflection layer is heavily doped, the conduction band will be bent, which will increase the height of the potential barrier layer and prevent transmission. Electrons in the P-cladding region. P-doping will also reduce the height of the barrier layer transmitting holes into the optical guiding region. The first electron reflection layer or at least one first reflection layer (if there are multiple reflection layers) may include Indium. The introduction of indium into the A1P or GaP strain layer will reduce the strain in the layer and therefore increase the critical thickness of the layer. The Γ electron reflection layer can be made thicker by this, which reduces the possibility of electrons passing through the layer. Electron reflection resistance The optical guide layer may be deposited on cladding region and P-doped region

O: \ 61 \ 61877.ptc Page 11 461164 _Case No. 88121986_ Year Month Amendment _ V. Description of Invention (9) Between domains. A second aspect of the present invention provides an optical semiconductor device including: an optical guiding region, an active region having at least one energy potential well, the active region being deposited in the optical guiding region, and being deposited in the optical guiding region On the other side of the η-doped and p-doped cladding regions, an electron reflecting layer for reflecting Γ electrons is deposited on the ρ side of the active region, and the Γ conduction band of the optical guiding region generally follows the electrons. The X-conducting band of the reflective layer deteriorates. This field of the invention points to a problem that illustrates the laser device described in the aforementioned reference S '. J. Chang et al. And U.S. Patent No. 5,095,024. In this field, the X-conducting band of the electron reflection layer is selected so that it generally deteriorates with the Γ-conducting band of the optical guiding region, which can prevent the formation of a quantum potential well for X-electrons in the Γ-electron reflecting layer. This can be achieved with a selection of the composition of the optical light guide area. WO 97/40560 discloses an (A1, Ga, In) P light-emitting diode. An A1P barrier layer is deposited between the active area of the LED and the p-type cladding region. However, this barrier layer will increase the limit of Γ electrons. A quantum potential well is formed in the conduction band. The depth of this quantum potential well is about 0.4 eV, and as explained above, the introduction of this quantum potential well will exacerbate the electron loss problem of the X-state via the LED p-doped cladding region. (AluGao. ^ OjInusP can form an optical guidance area, and A1P can form an electron reflection layer. This is a method that facilitates putting the second field of the present invention into a realistic (A 1, Ga, In) P system. The electron reflection layer may be a P-doped type. The electron reflection layer may be disposed in the optical guiding region and the P-doped cladding region.

O: \ 61 \ 61877.ptc Page 12 461164 Case No. 8812 1986 Modification of installation shot fr9 Structured quality limit limit separation score is (10) configurable description installation description. Dagger weeping, -Jian Wujia's Mingfa, Benming, detailed illustrations, examples of diagrams, diagrams attached, reference explanations, referenced by a single borrowing, Jane's, and zhao-style drawings carved this reality #, J 体 i 中 I., J, Zi Peng Zhangyu J ο Yun 1 2 Invite 344 5 167891 Volume map map map map map map map map map half map with solution 2 by] c 1 map map, A map into layer parameters , Ja when C overwrites C to use a shot-like package 4 (shown to make the class package root "use M, I. U .. t is, for the prime number is differentiated) ρ 尔 作 In Mo system ' The system of T1 a gold system, CGS, A) I1 structure of A1 p diagram: / (position, junction obviously) ρ four Ga in-band formula [11 aluminum, solution of internal high-level barrier structure Variation B-νί The shot of the solution of the difficult-to-understand image structure band ΤΓ graph CS., Lei Chengshi CH-shaped solid; the body has a covering pattern of the laser domain and the structure knot of the solution part A solution with a band step solution, the graph diagram is structured, and the part I and the clear structure diagram are structured by the regional structure example. Changed band diagram The practice includes repairing the solution of the volume of the body and the case of the light, and the modification of the equipment. The other parts are installed; the actual shooting layer is changed with a bright laser striker. The figure of the resistance of 556 is shown in the figure. CH-5 shows sil, l clearly shows the shoulder J. It is said. It is obvious that | ^ / (VI t The example of the figure shows the best example of the formula This book is an example of the entity that explains the structure of the map.

O: \ 61 \ 61877.ptc Page 13 ^ 461164 [―Case No. 88121986_Year ”_ Yue Xiu 5. Description of the Invention (11) It shows that the optical guide area of the SCH laser device 10 (or light Waveguide bow region) and the band structure of the p-doped cladding region 11. The optical guiding region 10 is deposited between the P-type cladding region 11 and the n-type cladding region (not shown in FIG. 4). An active region (not shown) having at least one energy potential well to provide laser oscillation is deposited in the optical guiding region 10. The specific embodiment of FIG. 4 is made of the (A1, Ga, Iη) P system, The optical guide 丨 area 10 is formed by (A 10.3 Ga. 7) 0521 nD. «P, and the cladding area is (AlxGaH). 52In "8P, where 0.5 < xS1.0. In the specific embodiment of Fig. 4, X is selected as 1 so that the cladding region 1 1 is formed by A 1Q 521 n0. 48P, and shown in Fig. 4 With energy a1q 52inQ 48p p-type cladding region. An electron reflection layer 12 formed by Αίρ is deposited between the optical guiding region 10 and the p-doped cladding region 1 1. The lattice constant of Α1Ρ is 5. 467 A However, the lattice constant of the optical guide region 10 is 5. 653A »(As mentioned above, (Al, Ga, ln) p with a mole fraction of indium of 0.48 (Al, Ga, ln) p will be lattice-paired to GaAs, so optically guided The lattice constant of the region will be equal to the lattice constant of GaAs.) The lattice constant of the cladding region is also 5.653A, because the cladding region has a mole fraction of indium of 0.48, so the electron reflection layer 12 and the optical guiding region The lattice mismatch between 1 and 10 is approximately 3.4% »In general, 'chaos will occur at the interface between two semiconductor materials with a 3.4% lattice mismatch, which is undesirable in this example. It is because these differences and defects will deteriorate the characteristics of the laser device. I know that if overlapping layers and growing Lattice mismatch between the layers rather + 'of the first atomic layer deposition occurs with the lattice constant of the strain of overlapping layers, so the formation of an adhesive interface. However, when grown in the thickness of the upper layer increases, with

O: \ 61 \ 6l877.ptc Page 14 461164 銮 88121986 Duo Zheng V. Description of the invention (12) Mass strain energy will increase until it reaches the critical thickness ’, where the thickness will lead to excess energy that is not suitable for differential discharge. This critical thickness exists first by j η

Van der Merwe is published in Journal of Applied Physics, Volume 34, page 123 (1962). The thickness of the electron reflecting layer 12 is preferably smaller than this critical thickness to avoid the occurrence of the difference. In this case, the electron reflection layer is in a strained state. In this specific embodiment, 'will be in a stretched strain state, because A1P has a lower lattice constant than the light wave guide region 10. As far as the lattice mismatch of 3.4% is concerned, the critical thickness at which unsuitable differential rows occur is estimated to be 16A, please refer to "Applied Physics Letters", Volume 47, No. 3, 32 by R. People, et al. 2- 3 2 4 pages (1 9 8 5). Therefore, in the specific embodiment of FIG. 4, the thickness of the electron reflection layer 12 is preferably 16 A or less. In the body A1P, the Γ-Γ band gap is 3.6 eV, and the Γ-X band gap is 2.5 eV. However, in the specific embodiment of FIG. 4, the A1P layer 12 is in a state of tensile strain, which will reduce the band gap from the 3.6 eV volume. The band gap is reduced to 3. 2 9 5 eV for light holes and 3.5 eV for heavy hole valence bands. Chin-Yu Yeh et al. "Physical Review B" Vol. 50 No. 4 No. 2 7 1 5-2 7 1 8 (19 9 4) illustrates the reduction of the band gap of the strained layer. Assuming a band offset of 7:30, the A1P electron reflective layer will introduce a 0.801 eV blocking layer and transport Γ electrons into the p-doped cladding region (this calculation uses the light hole band gap). The X-band in the optical guiding region 10 is higher than the Γ-band 0.15 eV ′. Thus, most of the electrons in the optical guiding region will be located in the Γ-band, and these Γ-electrons will be reflected back to the active region by the electron reflection layer 12. There is a simple calculation that electrons pass through a rectangular barrier layer. Only about 6% of the Γ electrons can pass through the bottom of the 0.8 A e V potential barrier layer with a thickness of 16 A (this calculation assumes that Γ

O: \ 61 \ 61877.ptc Page 15 461164 Case No. 88121986 _Ά said Amendment V. Description of the invention (13) The effective mass of the son is mo = 0.15). In fact, the electrons passing through the electron reflection layer in FIG. 4 may be lower than 6%, because the p-doped cladding region 11 is not adjacent to the electron reflection layer. The p-doped cladding region is formed by (AlxGahh. ^ Ino. 48P, where 0.5 < x $ l.〇, and has a Γ-Γ band gap of up to 2.7 eV. When the r-band deteriorates, the electrons transmitted through the A1P layer increase to about 13%. The light hole has a lower energy compared to the heavy hole valence band in the A 1 P layer 12 because this layer is under tensile strain The band gap of the conduction band light hole is 3_294 eV 'This will give a light hole with a potential blocking layer of 0.178 eV, which is approximately 26% of the holes penetrating this blocking layer and entering the optical guiding area 10. A1P layer 12 The conduction band heavy hole has a band gap of 3.497 eV, which generates a blocking layer of 0.239 e V for heavy holes (the heavy hole blocking layer is not shown in Figure 4). (Please note that the value of the Γ-Γ band gap in A1P may be Greater than (4. 4 eV), as suggested by Chin-Yu Yeh et al., And the band offset of the compressive strain layer may be 85:15 instead of 70:30, as D. Dawson et al. At These offsets are suggested in "Applied Physics Letters", Vol. 64 (7), page 8 92 (1 9 94). These offsets are used to increase the potential barrier set in Figure 4. In the specific embodiment of FIG. 4, the aluminum concentration in the optical light guiding area is selected so that the Γ band in the optical guiding area 10 will deteriorate with the X band in the A 1P layer 12. This It is possible to avoid the formation of X-electron quantum potential wells in the A1P layer, thus overcoming the problems of the device proposed by Chang et al. And U.S. Patent No. 5,509,024. Furthermore, for the A Ιηη coated area, Figure 4 The X-band in the X-band bottom of the inner p-doped cladding region is higher by 0.06 eV (when the cladding region has

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Li-'! ≫ Case No. 8812 1986 & month 461164 V. Description of the invention (14) The lower the Al Moore fraction, the lower the X-band potential). Therefore, some electrons in the optical guiding region 10 will face a potential blocking layer of 0.06 eV to transmit into the P-doped cladding region, which will limit them to the light guiding region. Therefore, I can understand that the structure illustrated in FIG. 4 provides a blocking layer for Γ electrons and X electrons. The A1P layer 12 provides a larger potential blocking layer for Γ electrons than the p-doped cladding layer 11. In comparison, in the conventional structure illustrated in FIG. 3, the X conduction band in the p-doped cladding region is lower than the X band in the optical guidance region. Therefore, in the conventional structure, the X-electron is transmitted from the optical guiding region into the cladding region, and no potential blocking layer exists. FIG. 5 illustrates a further specific embodiment of the present invention. This figure again shows a band gap structure of a SCH laser device manufactured using a (Al, Ga, In) P system and lattice-matched to GaAs. The P-shaped cladding region 11 is formed by (AlxGahhjIna. ^ P, where 0.5 < xS1.0, and preferably 0.7 < χ $ 1.〇. In the embodiment shown in FIG. 5, X is selected as 1. 〇, and the band energy shown in Figs. 5 and 9 is related to the AlQ.52Infl.48P cladding layer. Fig. 5 shows the active area 16 and n-type cladding area 17 of the laser device graphically. The active areas 16 and η The accuracy and composition of the type cladding region 17 is not relevant to the present invention, so it will not be described further. In this specific embodiment, the strain compensation barrier layer 14 is placed between the light guide region and the P-doped cladding region. The strain compensation barrier layer 14 includes an A1P layer 12 and an InP layer 13. The barrier layer 14 provides a potential barrier layer for Γ electrons and X electrons. Both the A1P layer 12 and the InP layer 13 are selected to have a thickness less than a critical thickness. Thickness, to avoid the occurrence of unsuitable differential rows. Therefore, the A1P layer 12 and the InP layer 13 are in a strained state.

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Case No. 88121986 4 611 ^ 4 V. Description of invention (15). As mentioned above, connected to FIG. 4, the A 1 P layer 12 is in a tensile strain state because its lattice constant is about 3.4%, which is lower than the optical guide region 10 (which matches the GaAs lattice). , So it has a lattice constant of 5. 6 5 3 A). However, the I nP layer is in a compressive strain state because its lattice constant is about 3.8%, which is higher than the lattice constant of the optical guide region 10. In the case where the layer is in a compressive strain state, the Γ band gap increases and the X band gap decreases. When the energy of the heavy hole zone is lower than that of the light hole zone, the deterioration of the valence band is separated. As mentioned above and referring to Fig. 4, the A1P layer 12 provides a potential blocking layer of 0.801 eV to the? Electrons in the optical guiding region 10. The thickness of the I η P layer is selected so that the first constrained state in the I n P layer will be above the X-band in the P-doped cladding region 11 and also on the human side? Above the X-band in layer 12. Therefore, the InP layer is used as an additional electron reflecting layer to manage the electrons passing through the A1P layer, which provides a 0.27 eV potential resistive layer to the X electrons in the optical guiding region 10. Therefore, the InP layer 13 can prevent electrons from being lost from the optical guiding region 10 through the X-state in the cladding region 11. The aluminum concentration of the optical guiding region 10 is preferably selected, so that the Γ band in the optical guiding region 10 will follow Deteriorating toward the X-band in the A1P layer 12 'to avoid the formation of a quantum potential well for X electrons in the A1P layer 12. To achieve this, the optical guide area is preferably formed by (Alo.sGao.Jo. ^ I η〇 · 48P. FIG. 9 illustrates the conduction band 0 Γ of the optical guide area and the P-type cladding area of the structure of FIG. 5. The electrons have energy E0, that is, the conduction band energy of the optical guiding region 10 will encounter a potential blocking layer with a thickness of 16A and 0.801 eV. As mentioned above and referring to FIG. 4, only about 6% of the Γ electrons are available Cross this barrier

O: \ 61 \ 61877.ptc Page 18, 2001.06.13.018 461164 _-Case No. 88121986_Year_Month_Revision_ _ V. Description of the invention (16) The bottom of the layer (assuming the effective mass is mQ = 〇. 1 5) . (In reality, due to the lack of a thick p-doped cladding region 11, the conduction band energy of the optical guiding region is hardly lost. Γ electrons with energy EQ X electrons will face the 0.275 eV potential provided by the inP layer 14. The blocking layer 'approximately 6% of X electrons with energy Efl will pass through this blocking layer, assuming effective mass mfl = 0.45. The energy Ei shown in Figure 9 is equal to the Γ band of the p-type cladding region. In the traditional SCH laser structure Here, as shown in Fig. 2, the electrons with energy Ei in the optical guiding area are not restricted. The possibility of these electrons transmitting from the optical guiding area 10 into the p-type cladding area 11 is the same, And these electrons will be lost. However, in the present invention, the Γ electrons with Ei energy have a potential blocking layer i to 0.5 2 6 eV, which is the result of the Alp layer 12 ^ about 87% has energy £! The electrons will be reflected back to the light guide region 10 by the a 1P layer 12, and only 13% of the electrons will escape the optical guide region 10 and enter the p-type cladding region 11 '. This improved limitation improves the laser diode's Efficiency and high-temperature operability ..., further advantages of the present invention The barrier layer 4 is strain-compensated because it forms a layer in a stretched strain state and a layer in a compressive strain state. Because the barrier layer 4 is strain-compensated, it can provide two or more barriers This step further improves the electron limitation in the optical guiding area 10. It can also provide an A i P / np superlattice blocking layer. Figure i 0 shows that the modification of the specific embodiment of FIG. 5 'which blocks The layer 14 is formed by two 41? Layers 12 and two ^ I η P layers 1 3, and FIG. 11 shows other modifications of FIG. 5, where the blocking layer 14 is a layer of four A1P layers 12 and four InP layers 13. Ultra-lattice structure. The use of strain-compensated barrier layers 14 has other further advantages. As above

O: \ 61 \ 61877.ptc Page 19 461164 _ Case No. 8812 January 5, 1986 Fifth, the description of the invention (17) As mentioned, the strain layer with a thickness exceeding the critical thickness will not occur, but it has been reported before that the strain compensation block Layer thickness 2 二 „3 is thicker than the sum of the critical thickness of each layer, and does not introduce defects into the layer. The strain compensation barrier with β degrees thicker than the sum of the critical thicknesses of A1P and InP can grow again. No mismatch will be formed. If a thicker electron ^ 1 barrier layer can grow without introducing defects ', more electrons can be reflected back to the optical guidance area, thus improving the limitation of the electrons "_' Figure 6 Explaining a further specific embodiment of the present invention, except that the Inp layer 14 is located between the optical guiding region 10 and the A1P layer 12, this is similar to the specific embodiment. Like the specific embodiments of FIGS. 4 and 5, FIG. 6 The amount shown inside is used for A 1 〇.521 η〇 · 48P coating area 'but according to the principle' type coating area is (eight 1 ^ {631_3 £) (^ 52 1 110.48? 'Where 0.5 < Another $ 1.0. The active region and the n-type coating region are not shown in FIG. 6. Specifically, here In the embodiment, the I ηρ layer 13 is made very thin, so that the first restricted state is located on the top of the potential well formed in the Γ band. In this specific embodiment, the x-electron main plane in the optical guiding region 10 0.27 5 eV potential barrier to the InP layer. As mentioned above and connected to Figure 9, only about 6% of the electrons can pass through this type of barrier. As a result, an X-electron may form in the A1P layer 12. Quantum potential wells are no longer that important, so there is no need to choose the synthesis of the optical guidance region, so that the Γ band will also deteriorate with the X band in the human layer. This is in terms of designing the LD structure. Provides greater freedom. In fact, the content χ of the optical guide region 10 can be increased to a value of about 0.5. In the specific embodiment illustrated in FIG. 6, the optical guide region 10 * (A1. 4Ga 〇.6) 〇.521 ~ .48? Formed. As a result, the potential barrier layer of Γ electrons was 0.75

O: \ 61 \ 61877.ptc Page 20

Lu Bu I Case No. 88121986 461164 Amendment-¾ V. Description of the invention (18) Figure 6 shows further fatigue of the specific embodiment A ^ F ++ · U, / S / n S 4 * ^ The worry is in the barrier layer 14 There is no tendency to capture thunder, H h L on the P-doped cladding region. ^

ain A electric / 冋 quantum potential well, penetrates the quantum potential well formed by electricity: resistance: layer of electricity 3 as shown by A1P: 12 and shows in FIG. 7 a further aspect of the present invention b ^ 1C.T n « In the specific embodiment, the GaP layer 15 ′, the GaP layer 15 and the InP layer 13 form the specific layer λα, which is the decisive barrier layer 14 in the example. The amount of band b shown in Fig. 7 is A 1 〇.52 I η0. 42 Ρ P type package "#!" Yue Qi; SI® U β1 Λ complex area 11, but in principle 'ρ type coating The region can be formed by (AlxGalx) n τ 1 π (ΐΐ7 λι # 4 as +, + w ·· 52 1 0.48 ρ layer, where 0.5 < χ $ 1.0. The inactive region and η-type package are not shown in Fig. 7 The covered area is a bulk G a P with a Γ-Γ band gap of 2. 9 e V and a Γ-X band gap of 2 · 3 e V. GaP has a lattice constant of 5.451 eV, which is given in comparison with (; ^ 5 The lattice mismatch of about 3.7%. Therefore, the GaP layer 15 in FIG. 8 will be in a tensile strain state, which will reduce the Γ-Γ band gap of the Ga P layer 15 to a value lower than the bulk GaP. However, it will increase the Γ-X band gap. Compared with the previous specific embodiment, the thickness of the GaP layer 15 must be lower than the critical thickness where improper differential discharge will occur. This critical thickness is also about 16 A. Use GaP instead The advantage of A1 P is that the holes in the valence band face a lower potential blocking layer. Figure 7 shows that the potential blocking layer of the hole is 0.1 2 4 e V, compared to 0.178 eV in Figures 5 and 6. Hole penetration has a thickness of 16A 0.124 eV: the probability of the blocking layer is about 33%. The possible disadvantage of the structure in Figure 7 is that the potential blocking layer of r electrons in the optical guiding region 10 is lower than the blocking layer in Figure 5. As shown in Figure 7 If the GaP _ layer 'Γ electron's potential blocking layer is 0.465 eV, compared to the A1P layer's

O: \ 61 \ 61877.ptc Page 21 2001.06.13.021 461164 _Case No. 88121986__ Year Month Day Amendment __ 5. Description of the invention (19) 0.801 eV. A 0.465 eV potential barrier layer with a thickness of 16A has approximately 11% probability of penetration, assuming an effective mass of mQ = 0.15. But as mentioned above, the probability of Γ electrons penetrating the P-doped cladding region is significantly lower than this calculated value, because a thick (AlGa) InP layer with up to 2_7 evr-Γ band gap is adjacent to the barrier Layer 14. The electrons in the light-guiding region 10 will deteriorate with the Γ band of the cladding region 11, and there is a possibility that approximately 18% of the electrons can penetrate the cladding region 11 from the barrier layer 14. In this specific embodiment, it is best to choose an aluminum composite with an optical guiding area of 10, so that its Γ band will deteriorate with the X band in the GaP layer, avoiding the formation of a quantum potential well that will trap X electrons. In the specific embodiment of FIG. 7, the mole fraction X of the optical guiding region 10 is selected, and x = 0.4 can achieve this purpose. FIG. 8 illustrates a further specific embodiment of the present invention. This example is similar to the example of FIG. 7, but the InP layer 13 is located between the GaP layer 15 and the optical guide region 10. Therefore, this specific embodiment corresponds to the specific embodiment of FIG. 6, but the GaP layer 15 replaces the A1P layer 12 of FIG. The band energy shown in FIG. 7 is used for A U · 52 〖nQ.48P p-type cladding area 1 1. However, in principle, the p-type cladding region can be (eight 13 ^ 31_3 £). .52111. A .48? Layer was formed, in which 0.5 < ^ $ 1.〇. The active region and the n-type cladding region are not shown in FIG. 8. For the above reasons, please refer to FIG. 6 '. The r-band in the optical guiding area does not need to deteriorate with the X-band in the GaP layer 15. This means that the aluminum concentration in the optical guide region can be selected more freely than the aluminum concentration in the optical guide region 10 in the specific embodiment of FIG. 7. In the specific embodiment of FIG. 8, the optical guide region may be formed of (AlQ.4GaQ.6) Q 52InG.48P. For an optically guided region with this composition, most of the electrons are located in the Γ band and enter the p-dopant during transmission.

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Year of the dagger month / 16 1 1 6 4 α 1 Case No. 88121986 V. Description of the invention (20) When the hetero-coated region 11 faces a potential blocking layer of 0.465 eV. Due to the lack of the InP layer, the X electrons in the optical guiding region 10 will face the 0.29 eV potential blocking layer. The potential blocking layer in the valence band to the hole injection is 0.124.eV. As in the specific embodiment of FIG. 6, the holes in the potential blocking layer formed by the Ga P layer 15 may be replaced into the light wave guiding region 10 and will be “radiated and penetrated” by the I nP layer 13. Quantum potential well in the valence band. In the specific embodiment described above, the electron reflecting layers 12, 13 and 15 are not doped, but these layers may be heavily p-doped. Doping the electron-reflecting layer will cause the band to bend, and this band bending will increase the height of the potential blocking layer that allows electrons to be transported from the optical guiding region 10 to the p-type cladding region 11, and the doped P-type blocking / blocking layer will also reduce the transmission The height of the barrier layer entering the hole in the optical guide area. ^ The present invention will be described with reference to the (A1, Ga, In) P alloy system, but the present invention is not limited to this specific alloy system. Those skilled in the semiconductor physical technology and electronic materials will appreciate the present invention because the present invention can be applied to any heterostructure laser device having a conduction band similar to that shown in FIG. 1. In the above specific embodiment, the electron reflection layers 12, 13, and 15 are located between the optical-guide area 10 and the P-doped cladding area 11, but is the electron reflection layer actually located in the optical guide area? The interface to the P-doped cladding region is not very important. In principle, the electron reflection layer can be deposited in the optical guide region 10 and in the P-side of the optical guide region. Furthermore, in principle, the electron reflection blocking layer can be located in the P-doped cladding region, but this is not good because once electrons penetrate into the ρ-doped cladding region, even if it is within the Γ band of the cladding region With the potential blocking layer, electrons will still be lost through the X state in the cladding region.

O: \ 61 \ 61877.ptc Page 23 2001.06.13. 023 ^ 461164 _Case No. 88121986_Year Month_Revision_ V. Description of the Invention (21) Although the present invention has been described with reference to the above SCH laser device, However, the present invention is not limited to the SCH laser device, but can be applied to other optical semiconductor devices, for example, it can be applied to other laser devices, such as a vertical cavity laser device, or a light emitting device such as a resonant cavity LED. Diode. INDUSTRIAL APPLICABILITY According to the above disclosure of the present invention, the present invention provides a barrier layer that can prevent the leakage of Γ electrons and X electrons, and also avoids the problem of loss of carriers through the X state in the P-doped cladding region, or at least Significant reduction because X-electrons and Γ electrons are reflected by the electron-reflective barrier layer. According to the above disclosure of the present invention, the X conduction band of the electron reflection layer is selected so that it will generally deteriorate with the Γ conduction band of the optical guide region, which can prevent the formation of X-electron quantum potential in the Γ electron reflection layer. Well, choosing the right optical guide area composition can achieve this goal.

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Claims (1)

Number 881219i Correction 461164 ^ t, patent application scope 1. An optical semiconductor device comprising: an active region; and a P-doped cladding region located on one side of the active region; wherein an electron reflection barrier is provided on the p side of the active region A layer for reflecting Γ electrons and X electrons. The electron reflection blocking layer provides a blocking layer for Γ electrons that is larger than a blocking layer for X electrons. 2. The optical semiconductor device according to item 1 of the patent application scope, wherein the electron reflection resistive layer includes a first electron reflection layer for reflecting Γ electrons, and a second electron reflection layer for reflecting X electrons. 3. For the optical semiconductor device according to item 1 of the patent application, wherein at least one of the electron reflecting layers is a strained layer. 4. For an optical semiconductor device according to item 3 of the patent application, one of the electronic reflective layers is in a compressive strain state and the other electronic reflective layer is in a tensile strain state. 5. The optical semiconductor device according to item 1 of the patent application scope, wherein the device is a shot. 6. The optical semiconductor device according to item 1 of the patent application scope, wherein the device is a laser device. 7. The optical semiconductor device according to item 6 of the patent application, wherein the device is a separation-restricted heterostructure laser device including an optical guiding area and an active area deposited in the optical guiding area. 8. The optical semiconductor device according to item 2 of the patent application, wherein the Γ electron reflection layer is located between the optical guide region and the X electron reflection layer. 9. For an optical semiconductor device according to item 8 of the patent application, wherein the optical O: \ 61 \ 61877.ptc Page 1 2001.09. 03. 026 461164 _ Case No. 88121986 _ Month and Day ___ 6. The Γ conduction band in the guidance area of the patent application will generally follow the X of the Γ electron reflection layer The conduction band deteriorates. 10. The optical semiconductor device according to item 2 of the patent application, wherein the Γ electron reflection layer is located between the X electron reflection layer and the P-doped cladding region. 11. The optical semiconductor device according to item 1 of the patent application, wherein the electron reflection blocking layer includes a plurality of first electron reflection layers for reflecting Γ electrons, and a plurality of first electron reflection layers for reflecting X electrons. 1 2. The optical semiconductor device according to item 11 of the application, wherein the electron reflection blocking layer has a superlattice structure. 1 3. The optical semiconductor device according to item 2 of the patent application scope, wherein the device is made of (Al, Ga, In) P system, and the Γ electron reflection layer is made of materials selected from the group consisting of A1P and GaP, The X-electron reflection layer is made of InP. 14. The optical semiconductor device according to item 11 of the scope of patent application, wherein the device is made of (A1, Ga, In) P system, and each Γ electron reflection layer is made of a material selected from the group consisting of A 1P and GaP Therefore, each X-electron reflection layer is made of I η P. 15. The optical semiconductor device according to item 9 of the patent application scope, wherein the Γ electron reflection layer is 8 1? And the optical guiding area is (8 1 (). 308 (). 7). .52111. .48 ?. 16. The optical semiconductor device according to item 13 of the patent application scope, wherein the thickness of each electron reflection layer is 16A or less. 1 7. The optical semiconductor device according to item 1 of the patent application scope, wherein at least one of the electron reflecting layers is a P-doped type. 1 8. The optical semiconductor device according to item 13 of the patent application scope, wherein the O: \ 61 \ 61877.ptc Page 2 2001.08.16. 027 ^ 461164 _ Case No. 88121986_ Month and year Amendment _ 6. Scope of patent application An electron reflection layer contains indium. 19. The optical semiconductor device according to item 7 of the application, wherein an electron reflective layer is deposited between the optical guiding region and the P-doped cladding region. 20. An optical semiconductor device comprising: an optical guiding region; an active region having at least one energy potential well, the active region being deposited in the optical guiding region; and η deposited on the other side of the optical guiding region Doped and p-doped cladding regions; wherein an electron reflection layer reflecting Γ electrons is provided on the p-side of the active region; and the Γ conduction band of the optical guiding region generally follows the X conduction band of the electron reflection layer deterioration. 2 1. The optical semiconductor device according to item 20 of the scope of patent application, wherein (ΑΙα. / Βο.Λ. ^ Ιπο. ^ P forms an optical guiding region, and an electron reflection layer is formed by A1P. 22. If the scope of patent application is The optical semiconductor device of item 20, wherein the electron reflection layer is of a p-doped type. 2 3. The optical semiconductor device of item 20 of the patent application scope, wherein the electron reflection layer is deposited on the optical guiding region and the p-doped Between the cladding regions. 2 4. The optical semiconductor device according to item 20 of the patent application scope, wherein the device is a separation-limiting heterostructure laser device. O: \ 61 \ 61877.ptc Page 3 2001.08.16.028